This is NOT a function because we have x = -5 repeating. The value x = -5 corresponds to y = 10 (column 1) and y = 8 (column 3). The value x = 5 repeats as well.
We can only have a function when every input leads to exactly one output.
If you graphed these points, it would fail the vertical line test. It is possible to pass a single vertical line through more than one point.
So once again, we don't have a function.